What are main points in the battle of Poitiers 1356 and Agincourt 1415?

The Battle of Portiers was one of three important English victories in the Hundred Years War. English troops under Edward the Black Prince were pursued by a much larger French army. They hid in thickets and bushes and attacked the French army when it became bogged down. The English longbow (roughly six feet) which could fire at long distances and cause arrows to rain down on horses and men, proved decisive. At the end of the battle, King John II of France was captured, and only released after agreeing to very unfavorable terms.

At Agincourt, an English army again encountered a much larger French force, but the outcome of the battle was determined in less than three hours in favor of the English. Again, the decisive factor was the English longbow. King Henry V led the English forces against the Constable of France, Charles d'Albret was killed. It was after Agincourt that Joan of Arc appeared as the savior of the French. In both battles, a superior French force was defeated by an English force which they should have been able to defeat easily.